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1.
Biol Lett ; 20(6): 20240066, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38836647

ABSTRACT

Metabolism drives various biological processes, potentially influencing the ecological success and evolutionary fitness of species. Understanding diverse metabolic rates is fundamental in biology. Mechanisms underlying adaptation to factors like temperature and predation pressure remain unclear. Our study explored the role of temperature and predation pressure in shaping the metabolic scaling of an invasive mussel species (Brachidontes pharaonis). Specifically, we performed laboratory-based experiments to assess the effects of phenotypic plasticity on the metabolic scaling by exposing the mussels to water conditions with and without predator cues from another invasive species (the blue crab, Callinectes sapidus) across various temperature regimes. We found that temperature effects on metabolic scaling of the invasive mussels are mediated by the presence of chemical cues of an invasive predator, the blue crab. Investigating temperature-predator interactions underscores the importance of studying the ecological effects of global warming. Our research advances our understanding of how environmental factors jointly impact physiological processes.


Subject(s)
Cues , Introduced Species , Predatory Behavior , Temperature , Animals , Brachyura/physiology , Bivalvia/physiology , Bivalvia/metabolism
2.
ESMO Open ; 8(3): 101198, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37119788

ABSTRACT

BACKGROUND: Metastatic colorectal cancer (mCRC) patients tend to have modest benefits from molecularly driven therapeutics. Patient-derived tumor organoids (PDTOs) represent an unmatched model to elucidate tumor resistance to therapy, due to their high capacity to resemble tumor characteristics. MATERIALS AND METHODS: We used viable tumor tissue from two cohorts of patients with mCRC, naïve or refractory to treatment, respectively, for generating PDTOs. The derived models were subjected to a 6-day drug screening assay (DSA) with a comprehensive pipeline of chemotherapy and targeted drugs against almost all the actionable mCRC molecular drivers. For the second cohort DSA data were matched with those from PDTO genotyping. RESULTS: A total of 40 PDTOs included in the two cohorts were derived from mCRC primary tumors or metastases. The first cohort included 31 PDTOs derived from patients treated in front line. For this cohort, DSA results were matched with patient responses. Moreover, RAS/BRAF mutational status was matched with DSA cetuximab response. Ten out of 12 (83.3%) RAS wild-type PDTOs responded to cetuximab, while all the mutant PDTOs, 8 out of 8 (100%), were resistant. For the second cohort (chemorefractory patients), we used part of tumor tissue for genotyping. Four out of nine DSA/genotyping data resulted applicable in the clinic. Two RAS-mutant mCRC patients have been treated with FOLFOX-bevacizumab and mitomycin-capecitabine in third line, respectively, based on DSA results, obtaining disease control. One patient was treated with nivolumab-second mitochondrial-derived activator of caspases mimetic (phase I trial) due to high tumor mutational burden at genotyping, experiencing stable disease. In one case, the presence of BRCA2 mutation correlated with DSA sensitivity to olaparib; however, the patient could not receive the therapy. CONCLUSIONS: Using CRC as a model, we have designed and validated a clinically applicable methodology to potentially inform clinical decisions with functional data. Undoubtedly, further larger analyses are needed to improve methodology success rates and propose suitable treatment strategies for mCRC patients.


Subject(s)
Colonic Neoplasms , Colorectal Neoplasms , Humans , Cetuximab/adverse effects , Colorectal Neoplasms/drug therapy , Colorectal Neoplasms/genetics , Colorectal Neoplasms/pathology , Mutation
3.
Mar Pollut Bull ; 186: 114396, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36462422

ABSTRACT

Habitat complexity is one of the main influences on biodiversity in marine environments, particularly in coastal areas where foundation seaweeds provide substrate for highly diverse communities. We studied the 2D and 3D fractal dimensions of Gongolaria montagnei (Fucales) over the vegetative season and examine their relationship with the abundance, species richness and morpho-functional groups of the gastropod associated. Overall, the 3D fractal analysis method used here better describes seaweeds structural complexity compared to the traditional 2D fractal analysis, as highlighted by the higher relationship with gastropod assemblage associated to the alga in terms of abundance, number of species and morpho-functional groups. We propose this new method as a valuable tool for understanding the relationship between seaweeds and associated fauna, which is critical for gaining a better understanding of the role that algal species play in a specific habitat and the consequences of their loss.


Subject(s)
Gastropoda , Phaeophyceae , Seaweed , Animals , Seaweed/chemistry , Fractals , Ecosystem , Biodiversity , Mollusca , Plants
4.
Mar Environ Res ; 173: 105515, 2022 Jan.
Article in English | MEDLINE | ID: mdl-34753049

ABSTRACT

Invasive seaweeds are listed among the most relevant threats to marine ecosystems worldwide. Biodiversity hotspots, such as the Mediterranean Sea, are facing multiple invasions and are expected to be severely affected by the introduction of new non-native seaweeds in the near future. In this study, we evaluated the consequences of the shift from the native Ericaria brachycarpa to the invasive Asparagopsis taxiformis habitat on the shallow rocky shores of Favignana Island (Egadi Islands, MPA, Sicily, Italy). We compared algal biomass and species composition and structure of the associated epifaunal assemblages in homogenous and mixed stands of E. brachycarpa and A. taxiformis. The results showed that the biomass of primary producers is reduced by 90% in the A. taxiformis invaded habitat compared to the E. brachycarpa native habitat. The structure of the epifaunal assemblages displayed significant variations among homogenous and mixed stands. The abundance, species richness and Shannon-Wiener diversity index of the epifaunal assemblages decreased by 89%, 78% and 40%, respectively, from homogenous stands of the native E. brachycarpa to the invasive A. taxiformis. Seaweed biomass was the structural attribute better explaining the variation in epifaunal abundance, species richness and diversity. Overall, our results suggest that the shift from E. brachycarpa to A. taxiformis habitat would drastically erode the biomass of primary producers and the associated biodiversity. We hypothesize that a complete shift from native to invasive seaweeds could ultimately lead to bottom-up effects on rocky shore habitats, with negative consequences for the ecosystem structure, functioning, and the services provided.


Subject(s)
Ecosystem , Seaweed , Biodiversity , Eutrophication , Mediterranean Sea , Sicily
5.
Mar Environ Res ; 166: 105279, 2021 Apr.
Article in English | MEDLINE | ID: mdl-33631361

ABSTRACT

Invasive seaweeds threaten biodiversity and socio-economics values of worldwide marine ecosystems. Understanding to what extent invasive seaweeds can modify local biodiversity is one of the main priorities in conservation ecology. We compared the molluscan assemblage of the invasive Asparagopsis taxiformis with that of the native Ericaria brachycarpa and explore if variation in the molluscan assemblage diversity was related to the substrate attributes (biomass, and thallus, canopy, and interstitial volumes) of the algae. Results showed that A. taxiformis harboured lower diversity and trophic structure of the molluscan assemblage compared to E. brachycarpa. Biomass was the variable that better explained the variation of abundance and number of species as well as the multivariate structure of the molluscan assemblage. Overall, our results suggest that a complete habitat shift from native to invasive species can potentially trigger bottom-up effects in rocky shores habitats, reducing the biodiversity and the services provided by the invaded habitat.


Subject(s)
Rhodophyta , Seaweed , Biodiversity , Ecosystem , Introduced Species
7.
Ann Oncol ; 29(5): 1203-1210, 2018 05 01.
Article in English | MEDLINE | ID: mdl-29635390

ABSTRACT

Background: BRCA1 and BRCA2 (BRCA1/2)-deficient tumors display impaired homologous recombination repair (HRR) and enhanced sensitivity to DNA damaging agents or to poly(ADP-ribose) polymerase (PARP) inhibitors (PARPi). Their efficacy in germline BRCA1/2 (gBRCA1/2)-mutated metastatic breast cancers has been recently confirmed in clinical trials. Numerous mechanisms of PARPi resistance have been described, whose clinical relevance in gBRCA-mutated breast cancer is unknown. This highlights the need to identify functional biomarkers to better predict PARPi sensitivity. Patients and methods: We investigated the in vivo mechanisms of PARPi resistance in gBRCA1 patient-derived tumor xenografts (PDXs) exhibiting differential response to PARPi. Analysis included exome sequencing and immunostaining of DNA damage response proteins to functionally evaluate HRR. Findings were validated in a retrospective sample set from gBRCA1/2-cancer patients treated with PARPi. Results: RAD51 nuclear foci, a surrogate marker of HRR functionality, were the only common feature in PDX and patient samples with primary or acquired PARPi resistance. Consistently, low RAD51 was associated with objective response to PARPi. Evaluation of the RAD51 biomarker in untreated tumors was feasible due to endogenous DNA damage. In PARPi-resistant gBRCA1 PDXs, genetic analysis found no in-frame secondary mutations, but BRCA1 hypomorphic proteins in 60% of the models, TP53BP1-loss in 20% and RAD51-amplification in one sample, none mutually exclusive. Conversely, one of three PARPi-resistant gBRCA2 tumors displayed BRCA2 restoration by exome sequencing. In PDXs, PARPi resistance could be reverted upon combination of a PARPi with an ataxia-telangiectasia mutated (ATM) inhibitor. Conclusion: Detection of RAD51 foci in gBRCA tumors correlates with PARPi resistance regardless of the underlying mechanism restoring HRR function. This is a promising biomarker to be used in the clinic to better select patients for PARPi therapy. Our study also supports the clinical development of PARPi combinations such as those with ATM inhibitors.


Subject(s)
Biomarkers, Tumor/genetics , Breast Neoplasms/drug therapy , Drug Resistance, Neoplasm/genetics , Poly(ADP-ribose) Polymerase Inhibitors/pharmacology , Rad51 Recombinase/genetics , Animals , BRCA1 Protein/genetics , BRCA2 Protein/genetics , Breast/pathology , Breast Neoplasms/genetics , Breast Neoplasms/pathology , Drug Resistance, Neoplasm/drug effects , Female , Germ-Line Mutation , Humans , Mice , Mice, Nude , Poly(ADP-ribose) Polymerase Inhibitors/therapeutic use , Recombinational DNA Repair/drug effects , Recombinational DNA Repair/genetics , Retrospective Studies , Treatment Outcome , Xenograft Model Antitumor Assays
8.
Ann Oncol ; 29(6): 1454-1460, 2018 06 01.
Article in English | MEDLINE | ID: mdl-29648575

ABSTRACT

Background: Papillary thyroid cancer (PTC) is the most common thyroid carcinoma and exhibits an almost uniformly good prognosis, while anaplastic thyroid cancer (ATC) is less frequent and is one of the most aggressive cancers usually resistant to conventional treatment. Current hypothesis posits that ATC derives from PTC through the progressive acquisition of a discrete number of genomic alterations and implies that the mutational landscape of ATC resembles that of PTC. However, the clinical behaviour of ATC and PTC is radically different. We decided to address the disconnection between the clinical behaviour of ATC and PTC and the proposed model of the progressive development of ATC from PTC. Patients and methods: We carried out exome sequencing of DNA from 14 ATC specimens including three cases of concomitant ATC and PTC as well as their corresponding normal DNA from 14 patients. The sequencing results were validated using droplet digital PCR. We carried out immunohistochemistry and immunofluorescence studies of the concomitant ATC and PTC cases. In addition, we integrated our sequencing results with the existing TCGA data. Results: Most of the somatic mutations identified in the ATC component differed from the ones in PTC in the cases of concomitant ATC and PTC. The trunks of the phylogenetic trees representing the somatic mutations were short with long branches. In one case of concomitant PTC and ATC specimens, we observed an infiltration of PTC cells within the ATC component. Moreover, we integrated our results with data obtained from TCGA and observed that the most frequent mutations found in ATC presented high cancer cell fraction values and were significantly different from the PTC ones. Conclusion: ATC diverge from PTC early in tumour development and both tumour types evolve independently. Our work allows the understanding of the relationship between ATC and PTC facilitating the clinical management of these malignancies.


Subject(s)
Biomarkers, Tumor/genetics , Clonal Evolution , Thyroid Cancer, Papillary/pathology , Thyroid Carcinoma, Anaplastic/pathology , Thyroid Neoplasms/pathology , Humans , Mutation , Phylogeny , Prognosis , Thyroid Cancer, Papillary/genetics , Thyroid Carcinoma, Anaplastic/genetics , Thyroid Neoplasms/genetics , Exome Sequencing
9.
Mar Pollut Bull ; 129(2): 762-771, 2018 Apr.
Article in English | MEDLINE | ID: mdl-29108739

ABSTRACT

We analyzed the occurrence and status of infralittoral fringe populations of Cystoseira spp. (Fucales) at thirteen rocky sites around the Italian coastline, and explored the relationships with relevant environmental and anthropogenic variables. We found Cystoseira populations at 11 sites: most were scattered and comprised monospecific stands of C. compressa, and only 6 sites also supported sparse specimens of either C. amentacea var. stricta or C. brachycarpa. Coastal human population density, Chlorophyll a seawater concentrations, sea surface temperature, annual range of sea surface temperature and wave fetch explained most of the variation of the status of C. compressa. We hypothesize a generally unhealthy state of the Italian Cystoseira infralittoral fringe populations and identify multiple co-occurring anthropogenic stressors as the likely drivers of these poor conditions. Extensive baseline monitoring is needed to describe how Cystoseira populations are changing, and implement a management framework for the conservation of these valuable but vulnerable habitats.


Subject(s)
Environmental Monitoring/methods , Phaeophyceae/growth & development , Seawater/chemistry , Chlorophyll/analysis , Chlorophyll A , Ecosystem , Human Activities , Humans , Italy , Mediterranean Sea , Population Density , Temperature , Urbanization
10.
Knee Surg Sports Traumatol Arthrosc ; 25(3): 669-674, 2017 Mar.
Article in English | MEDLINE | ID: mdl-27017212

ABSTRACT

PURPOSE: Lateral progression of arthritis following medial unicompartmental knee arthroplasty (UKA), although infrequent, is still the most common reason for revision surgery. Treatment options normally include conversion to total knee arthroplasty. An alternative strategy for some patients may be addition of a lateral UKA. We report the first results of staged bi-compartmental UKA (Bi-UKA) strategy. METHODS: We retrospectively selected from our UKA database patients who underwent a lateral UKA to treat a symptomatic lateral osteoarthritis progression after a medial UKA. The analysis included a clinical and radiological assessment of each patient. RESULTS: Twenty-five patients for a total of 27 knees of staged Bi-UKA were carried out in a single centre. The mean time interval between primary medial UKA and the subsequent lateral UKA was 8.1 years (SD ± 4.6 years). The mean age at the time of the Bi-UKA was 77.1 years (SD ± 6.5 years). The median hospital stay was 3 (range 2-9 days) days, and the mean follow-up after Bi-UKA was 4 years (SD ± 1.9 years). The functional scores showed a significant improvement as compared to the pre-operative status (paired t test, p = 0.003). There were no radiological evidences of failure. None of the patients needed blood transfusion, and there was no significant complications related to the surgical procedure without further surgeries or revisions at final follow-up. CONCLUSIONS: These results suggest that addition of a lateral UKA for arthritis progression following medial UKA is a good option in appropriately selected patients. LEVEL OF EVIDENCE: Observational study without controls, Level IV.


Subject(s)
Arthroplasty, Replacement, Knee/methods , Osteoarthritis, Knee/surgery , Reoperation/methods , Aged , Databases, Factual , Disease Progression , Female , Humans , Knee Joint/surgery , Knee Prosthesis , Length of Stay , Male , Middle Aged , Patient Selection , Radiography , Range of Motion, Articular , Retrospective Studies , Treatment Outcome
11.
Acta Biomed ; 85 Suppl 2: 20-4, 2014 Sep 24.
Article in English | MEDLINE | ID: mdl-25409714

ABSTRACT

BACKGROUND AND AIM OF THE WORK: Subscapularis tendon lesions, in particular the isolated ones, are often not recognized and undervalued, so in the literature they are described with a variable incidence. Aim of the work is presenting our experience with the short to medium term follow up results of the arthroscopic repair of isolated subscapularis lesions. METHODS: We retrospectively analyzed 311 shoulder arthroscopies performed by a single senior surgeon, from which we have found 10 isolated subscapularis lesions. After the arthroscopic repair of subscapularis tendon the patients have been evaluated with a median follow up of 17.7 months with specific tests for the subscapularis (Napoleon's and lift off tests) and clinical scores (Constant and UCLA scores). RESULTS: We have obtained the tests negativization with an internal rotation level up to D8. The Constant score reached 86.7 with a median improvement of 49.4 points. The UCLA score at the last follow up was 30.8 with a median improvement of 20.1 points. CONCLUSIONS: Isolated subscapularis lesions are uncommon and often they are not correctly diagnosed. Arthroscopy has a decisive role in both the diagnostic and therapeutic side, with good short to medium term results.


Subject(s)
Arthroscopy , Rotator Cuff Injuries , Tendon Injuries/diagnosis , Tendon Injuries/surgery , Female , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Range of Motion, Articular , Retrospective Studies , Shoulder Joint
12.
J Control Release ; 192: 249-61, 2014 Oct 28.
Article in English | MEDLINE | ID: mdl-25111130

ABSTRACT

Neonatal porcine Sertoli cells (NPSC) are immune privileged cells showing innate phagocytic and antibacterial activities. NPSC have been shown capable of immunoaltering the body's response and possess lung homing capacity. These properties encourage investigation of NPSC as functional components of cell-based therapeutic protocols to treat lung infections and related complications. In this work, for the first time, NPSC were tailored to carry an antibiotic drug loaded into poly(d,l lactic) acid microparticles (MP). A loading protocol was developed, which afforded 30% drug uptake and high stability over time, with little or no effects on NPSC viability, morphology, reactive oxygen species production and DNA integrity. FSH receptor integrity, and TGFß (transforming growth factor ß) and AMH (anti-Müllerian hormone) expressions were unchanged after 1month of cryopreservation. Protein tyrosine kinase activation due to phagocytosis may have had resulted in changes in inhibin B expression. The activity of MP-loaded or NPSC alone against Pseudomonas aeruginosa was maintained throughout 1month of storage. NPSC couple an innate antibacterial activity with the capacity to embody drug loaded MP. We showed for the first time that engineered NPSC can be cryopreserved with no loss of their basic properties, thereby possibly representing a novel approach for cell-based therapeutic and drug delivery system.


Subject(s)
Anti-Bacterial Agents/administration & dosage , Drug Delivery Systems/methods , Ofloxacin/administration & dosage , Sertoli Cells/cytology , Animals , Anti-Bacterial Agents/pharmacology , Cells, Cultured , Cryopreservation , Male , Ofloxacin/pharmacology , Pseudomonas Infections/drug therapy , Pseudomonas aeruginosa/drug effects , Sertoli Cells/metabolism , Swine
13.
Transplant Proc ; 46(6): 1999-2001, 2014.
Article in English | MEDLINE | ID: mdl-25131093

ABSTRACT

Insulin resistance in type 2 diabetes mellitus (T2DM) may be due to a chronic inflammation of the visceral adipose tissue (VAT) leading to local and systemic increases in proinflammatory cytokines. Microencapsulated porcine Sertoli cells (MC-pSC), by provision of immunomodulatory and trophic factors, have been successfully used to reduce such inflammation in rodent animal models of type 1 diabetes with no complications or deleterious side effects. Herein, we have begun to investigate this novel and safe therapeutic approach in the spontaneously obese nonhuman primate with spontaneous, insulin-dependent T2DM. After MC-pSC intraperitoneal injection we have evaluated, throughout a 6-month follow-up period, daily ad libitum fed glucose levels, daily exogenous insulin supplementation, biweekly body weight measurements, periodic fasting blood glucose concentrations, glycated hemoglobin (HbA1c) levels, glucose tolerance tests (GTT), and fluorescence-activated cell sorting cytometry (FACS) assessment of peripheral blood mononuclear cells. Very preliminarily, we have observed a slight reduction in fasting (FPG) and mean nonfasting (NF) plasma glucose levels. We found minimal changes, only in 1 animal, in daily exogenous insulin requirements and HbA1c levels. Flow cytometric analysis was associated with decrease in CD8(+) cells only in 1 recipient with a reduction in mean regulatory T Cells (Treg), whereas interestingly, decrease of B lymphocytes was observed in both animals. These results may suggest that this novel MC-SC-based transplantation protocol might possibly impact the metabolic status of T2DM in higher mammals that are close to humans.


Subject(s)
Cell- and Tissue-Based Therapy/methods , Diabetes Mellitus, Type 2/therapy , Sertoli Cells/transplantation , Transplantation, Heterologous , Animals , Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/etiology , Drug Compounding , Glycated Hemoglobin/metabolism , Hypoglycemic Agents/therapeutic use , Injections, Intraperitoneal , Insulin/therapeutic use , Insulin Resistance/physiology , Macaca mulatta , Male , Obesity/complications , Swine
14.
J Biol Regul Homeost Agents ; 27(3): 805-16, 2013.
Article in English | MEDLINE | ID: mdl-24152845

ABSTRACT

Cadmium (Cd), an ubiquitous environmental metal, mainly used for industrial purposes, may be toxic at level of the reproductive system. Testis tubular-based Sertoli cells (SC), play a major role in constituting the blood-testis barrier and provide a unique microenvironment for the genesis and differentiation of germ cells. Hence SC strictly control sperm qualitative and quantitative parameters. We aimed to assess whether exposure to Cd would adversely affect superior mammal SC viability and function. We isolated and purified SC from pre-pubertal pig testes according to our method and incubated the retrieved cells with three different Cadmium chloride concentrations (5-10-15 microM). Parameters of SC function such as inhibin B and anti-Mullerian hormone (AMH) were depressed by Cd exposure, contrary to what observed in untreated controls. No impairment of the FSH receptor integrity on the SC, as assessed by 17-beta-estradiol production, upon stimulation with FSH, was observed in either 5 microM Cd-treated or untreated controls. Differences, on the contrary, were observed for higher Cd concentrations (10 and 15 mM), in terms of FSH receptor integrity, that was altered, as compared to untreated controls, in terms of lower production of 17-beta-estradiol. In addition, the apoptotic test showed a significant increase of early (ANNEXIN V-/Propidium Iodide+) (AV-/PI+) and late apoptotic cells (AV+/ PI+) in all Cd -treated SC conditions as compared to controls. In conclusion, the Cd -related toxicity on SC, clearly demonstrated by our study, even at low concentrations, is expected to damage spermatogenesis that directly is dependent upon retention of SC viability and function.


Subject(s)
Cadmium/toxicity , Sertoli Cells/drug effects , Animals , Anti-Mullerian Hormone/metabolism , Apoptosis/drug effects , Cadmium/pharmacokinetics , Cell Survival/drug effects , Inhibins/metabolism , Male , Receptors, FSH/drug effects , Receptors, FSH/physiology , Sertoli Cells/physiology , Swine
17.
J Biomater Appl ; 23(2): 123-45, 2008 Sep.
Article in English | MEDLINE | ID: mdl-18467747

ABSTRACT

The optimization, through a Design of Experiments (DoE) approach, of a microencapsulation procedure for isolated neonatal porcine islets (NPI) is described. The applied method is based on the generation of monodisperse droplets by a vibrational nozzle. An alginate/polyornithine encapsulation procedure, developed and validated in our laboratory for almost a decade, was used to embody pancreatic islets. We analyzed different experimental parameters including frequency of vibration, amplitude of vibration, polymer pumping rate, and distance between the nozzle and the gelling bath. We produced calcium-alginate gel microbeads with excellent morphological characteristics as well as a very narrow size distribution. The automatically produced microcapsules did not alter morphology, viability and functional properties of the enveloped NPI. The optimization of this automatic procedure may provide a novel approach to obtain a large number of batches possibly suitable for large scale production of immunoisolated NPI for in vivo cell transplantation procedures in humans.


Subject(s)
Alginates/chemistry , Biocompatible Materials/chemistry , Cell Culture Techniques/instrumentation , Cell Transplantation/methods , Islets of Langerhans Transplantation/methods , Islets of Langerhans/cytology , Animals , Animals, Newborn , Capsules , Cell Culture Techniques/methods , Cell Survival , Cell Transplantation/instrumentation , Equipment Design , Equipment Failure Analysis , Glucuronic Acid/chemistry , Hexuronic Acids/chemistry , Islets of Langerhans Transplantation/instrumentation , Materials Testing , Rabbits , Swine , Vibration
19.
Transplant Proc ; 38(4): 1156-7, 2006 May.
Article in English | MEDLINE | ID: mdl-16757293

ABSTRACT

To comply with regulatory restrictions, with regard to graft of human islets immunoprotected within artificial microcapsules, into patients with type 1 diabetes mellitus (T1DM) with no recipient immunosuppression, we have prepared standard protocols on: (1) sodium alginate purification (clinical grade) for microcapsule fabrication; (2) preparation of biocompatible and permselective microcapsules containing human islets; and (3) minimally invasive techniques for grafting of the encapsulated human islets into the recipients' peritoneal cavity. As to no. 1, starting from pharmaceutical grade, raw sodium alginate powder, we prepared a pyrogen- and endotoxin-free 1.6% alginate solution by means of dialysis, multiple filtrations, and dilution/osmolality adjustments. As to no. 2, we have selected human islet preparations associated with >80% purity/viability, which underwent careful functional quality control testing prior to encapsulation; namely, most capsules contained one islet. As for no. 3, we have devised a simple intraperitoneal injection method under abdominal echography guidance with only local anesthesia to deposit the encapsulated islets in saline within the peritoneal leaflets. These technical protocols were officially approved by the Italian Ministry of Health which has released permission to conduct a phase I, closed human trial in 10 patients using encapsulated human islet grafts into nonimmunosuppressed patients with T1DM.


Subject(s)
Capsules , Diabetes Mellitus, Type 1/surgery , Islets of Langerhans Transplantation/methods , Clinical Trials, Phase I as Topic , Humans , Immunosuppression Therapy , Islets of Langerhans/cytology , Islets of Langerhans/physiology , Islets of Langerhans Transplantation/immunology , Italy , Tissue and Organ Harvesting/methods
20.
Transplant Proc ; 37(6): 2715-8, 2005.
Article in English | MEDLINE | ID: mdl-16182792

ABSTRACT

Short-term stimulation with insulinotropic factors may induce morphologic and functional changes in primary ductal cell cultures as a potential source of stem cells. We sought to assess the capacity of hepatocyte growth factor (HGF) to induce expression and maturation of proteins--PDX-1 and GLUT-2--and the subsequent beta-cell secretory profiles. HGF, which is involved in pancreatic development, may induce islet beta-cell neogenesis. Primary ductal cell monolayers were cultured in Click's + FBS 10% at 37 degrees C until tissue confluence. The medium was enriched with HGF (10 ng/mL for different periods); controls were treated for similar times with normal culture medium. At the end of the study, three-dimensional islet-like cell aggregates were observed in both conditions. In all conditions immunostaining studies showed positivity for the major endocrine-phenotype cell markers: insulin, PDX-1, glucokinase, and GLUT-2. Furthermore, treatment with HGF for short periods induced the expression of a functionally active, phosphorylated isoform of PDX-1. Finally, we observed that under basal conditions the cells initially and progressively released proinsulin throughout 5 days in all settings. Thereafter proinsulin was gradually replaced by insulin in the culture medium, reflecting a maturation progress. This pattern of insulin maturation and release was more evident when the cells were continuously stimulated with HGF for 12 days. The employed stimuli seemed to differentiate the original ductal cell layers toward endocrine cell phenotypes that synthesize and release proinsulin and subsequently insulin. HGF seems to provide a more efficient differentiation.


Subject(s)
Pancreatic Ducts/cytology , Animals , Animals, Newborn , Cell Culture Techniques/methods , Glucokinase/metabolism , Hepatocyte Growth Factor/physiology , Homeodomain Proteins/biosynthesis , Immunohistochemistry , Insulin/biosynthesis , Pancreatic Ducts/physiology , Swine , Trans-Activators/biosynthesis
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